This application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C. xc2xa7119 from our application entitled SIDE BAR FOR FLAT PANEL DISPLAY DEVICE, MANUFACTURING METHOD THEREOF, AND FLAT PANEL DISPLAY DEVICE HAVING SIDE BAR filed with the Korean Industrial Property Office on Oct. 15, 2001 and there duly assigned Ser. No. 2001-63450, and an application entitled SIDE BAR FOR FLAT PANEL DISPLAY DEVICE, MANUFACTURING METHOD THEREOF, AND FLAT PANEL DISPLAY DEVICE HAVING SIDE BAR filed with the Korean Industrial Property Office on Feb. 20, 2002 and there duly assigned Ser. No. 2002-9011.
1. Technical Field
The present invention relates to a flat panel display device, and more particularly, to a side bar used for sealing a faceplate to a backplate while being positioned between the faceplate and the backplate and maintaining a cell gap between the two plates. The present invention also relates to a method of manufacturing the side bar, and to a flat panel display device, in particular to a field emission display device, having the side bar.
2. Related Art
Generally, unlike a cathode ray tube which requires a large space and high voltage, a flat panel display device (FPD) is thin and substantially flat and it can be operated by low voltage. Flat panel display devices include a field emission display device (FED), a vacuum fluorescent display device (VFD), and a plasma display device (PDP).
Each flat panel display device differs in detailed structure depending on its type. However, every type of flat panel display device has electrodes disposed between two opposing plates, and the electrodes are operated to emit electrons. A phosphor layer formed on one of the plates is excited by the emitted electrons, and thus a predetermined pattern can be displayed.
The inner space between the plates is preferably maintained to be a vacuum so as to permit electrons to move easily. In order to maintain the inner space vacuum, the borders of the two plates are sealed with frit or with side bars provided with adhesive paste such as frit.
Side bars have been manufactured by cutting a flat glass plate at regular intervals. Both surfaces of the flat glass plate are provided with adhesive paste.
If the two plates are sealed with such a side bar, the cell gap between the two opposing plates of the flat panel display may not be uniform because of the amount of adhesive paste provided on both surfaces of the side bar. In other words, if more or less than the predetermined amount of adhesive paste is provided, the cell gap may be higher or lower than the predetermined height.
However, if a side bar having a height equivalent to a desired cell gap is employed for sealing, and the amount of adhesive paste provided on the side bar is reduced in order to resolve the above problem, the two plates may not be sufficiently sealed and they may leak.
It is difficult to manufacture a flat panel display which has a uniform gap between the two plates. In the case of a flat panel display having a gap between the two plates which is not uniform, brightness is also not uniform. Further, the pressure is not applied regularly to every spacer but is concentrated at a specific portion, and as a result, the spacer tends to break easily.
In order to improve the vacuum degree by removing gas generated while the electrodes and phosphor layers on the plates are fired, a getter is provided between the two plates or inside the exhaust pipe.
Getters employed for a flat panel display device are classified as evaporation-type getters and non-evaporation-type getters. The evaporation-type getter is being widely used for VFDs because of its low cost, but it generates particles during the activation process, it requires a substantial space to evaporate and deposit, and the activation temperature is relatively high. Hence, interest is now being focused on the non-evaporation-type getter.
A non-evaporation-type getter includes various types, such as a band-type and a ring-type. Due to convenience of use and low activation temperature, the band-type getter is widely employed for various fields.
There are basically two methods of providing a getter for a flat panel display. One is a method of providing the getter in an extra space outside the panel, and the other is a method of providing the getter in a space inside the panel.
Japanese Patent Laid-Open No.9-129161 discloses an FED according to a method of providing the getter in an extra space outside the panel. In this FED, first and second substrates are provided, a getter chamber is provided at the bottom of the second substrate, and the inner space between the first substrate and the second substrate communicates with the getter chamber via a connecting hole formed on the second substrate. An exhaust port is formed on the bottom of a glass which forms the getter chamber, and an exhaust tube is connected to the exhaust port. The getter is provided in the interior of the getter chamber using a getter support tool.
The getter support tool comprises a base section which has a band shape that is longer than the circumference of the getter, a hold section which is bent in a direction perpendicular to the surface of the base section and which grasps the getter from above and below, and support legs which are formed in one body with the base section and that maintain the getter at a predetermined height in the getter chamber.
Therefore, the amount by which the display in such a flat panel display as described above can be made thinner is limited because the getter chamber and the exhaust tube are provided at the bottom of the second substrate.
Further, the hold section must be bent for providing the getter to the getter support tool, and when the getter is provided inside the getter chamber, one of the support legs must be fixed on the getter chamber to prevent the getter support tool from deviating from its original position. Hence, it is inconvenient to fix the getter in the display device.
Korean Patent Laid-Open No.1999-43844 discloses another method of holding and activating a getter of an FED.
The method comprises forming a getter chamber and an exhaust tube on one side of a panel when manufacturing a flat panel display by aligning an upper substrate with a lower substrate and sealing them together, inserting the getter into the getter chamber after fixing the getter on a dummy wire by welding, enveloping the exhaust tube with the dummy wire by melting the exhaust tube, and activating the getter by heating after a process of exhaust and tip-off.
According to the above method, the flat panel display can be thinner than in the former case. However, a section of exhaust tube must be fixed on each side of the substrate, and the getter welded to the dummy wire must be inserted into the getter chamber through the exhaust tube. Hence, it is still inconvenient to fix the getter in the display device. Further, the quality of image display may be deteriorated due to the effects of heat on the substrate when the exhaust tube is melted using a torch.
When the getter is provided to the inner space of the panel, an extra structure, such as a metal wire or a getter holder, is usually employed to fix the getter. However, by using such an extra structure, the length of the process may increase and unnecessary space in addition to the effective area may also increase.
It is an object of the present invention to provide a side bar and a method of manufacturing thereof, which is capable of sealing a faceplate to a back plate of a flat panel display device and of maintaining a constant cell gap between two plates.
It is another object of the present invention to provide a side bar, and a method of manufacturing thereof, which has a getter-receiving portion in its body, and which is capable of sealing a faceplate to a back plate of a flat panel display device.
It is another object of the present invention to provide a flat panel display device having the above side bar. Because of such side bar, a non-effective area may be minimized and the process of providing the getter may be simplified.
A side bar for a flat panel display device according to a preferred embodiment of the present invention includes: contacting surfaces confronting the facing surfaces of the faceplate and the backplate of the flat panel display device; and at least one paste-receiving groove formed on each of the contacting surfaces in a longitudinal direction, the paste-receiving groove receiving adhesive paste for sealing the faceplate to the backplate of the flat panel display device.
The paste-receiving groove has a cross section selected from the group consisting of a wedge-shaped cross section, a semicircular cross section, and a rectangular cross section.
The paste-receiving groove may be formed so as to have one of the walls of the paste-receiving groove open.
The adhesive paste is provided to the paste-receiving groove so as to have a protrusion along the center of the adhesive paste, the protrusion being higher than the contacting surface of the side bar.
A method of manufacturing a side bar for a flat panel display device according to a preferred embodiment of the present invention includes: providing a plate; forming a plurality of paste-receiving grooves on the plate at regular intervals, the paste-receiving grooves receiving adhesive paste for sealing the faceplate to the backplate of the flat panel display device; disposing the adhesive paste in the paste-receiving grooves such that the adhesive paste has substantially the same height as the surface of the plate; drying the adhesive paste disposed in the paste-receiving grooves; disposing adhesive paste on the top surface of the adhesive paste disposed in the paste-receiving grooves so as to form protrusions along the top surface of the adhesive paste disposed in the paste-receiving grooves, the protrusion being higher than the surface of the plate; drying the adhesive paste disposed on the top surface of the adhesive paste disposed in the paste-receiving grooves; firing the plate with the disposed adhesive paste; and cutting the plate into a plurality of units, each unit including at least one paste-receiving groove.
A side bar for a flat panel display device according to another embodiment of the present invention includes: contacting surfaces confronting the facing surfaces of the faceplate and the backplate of the flat panel display device; at least one paste-receiving groove formed on each contacting surface in a longitudinal direction, the paste-receiving groove receiving adhesive paste for sealing the faceplate to the backplate of the flat panel display device; and at least one getter-receiving groove formed adjacent to the paste-receiving groove, the getter-receiving groove receiving a getter that is used for improving a vacuum degree of the flat panel display device.
The side bar may further comprise a communicating groove by which the getter-receiving groove communicates with an effective area of the flat panel display device that is to realize images. The communicating groove has side walls which can prevent the getter from deviating from the communicating groove.
The side bar may further comprise at least one wire-receiving groove formed so as to extend from the getter-receiving groove and to cross the paste-receiving groove, the wire-receiving groove receiving a metal wire for heating the getter.
The getter-receiving groove is formed into a unitary groove along the side bar in the longitudinal direction. Alternatively, the getter-receiving groove comprises a plurality of circular or rectangular-shaped grooves.
A method of manufacturing a side bar for a flat panel display device according to another embodiment of the present invention includes: providing a plate; forming a plurality of paste-receiving grooves at regular intervals and at least one getter-receiving groove adjacent to each paste-receiving groove on the plate, the paste-receiving groove receiving adhesive paste for sealing the faceplate to the backplate of the flat panel display device; and cutting the plate into a plurality of units, each unit including at least a paste-receiving groove and the getter-receiving groove that is adjacent to the paste-receiving groove.
The method of manufacturing a side bar may further comprise: forming a plurality of paste-receiving grooves and getter-receiving grooves on the plate; disposing the adhesive paste in the paste-receiving grooves; drying the adhesive paste disposed in the paste-receiving grooves; and firing the plate with the disposed adhesive paste.
A flat panel display device according to an embodiment of the present invention includes: a backplate and a faceplate which face each other; a cathode electrode provided on the backplate; an emitter provided on the cathode electrode, the emitter emitting electrons when an electric field is formed around the emitter; an anode electrode provided on the faceplate; a phosphor layer provided on the anode electrode, the phosphor layer being excited by the electrons emitted from the emitter and emitting light; and a side bar for sealing the faceplate to the backplate while being disposed between the faceplate and the backplate and maintaining a constant cell gap between the two plates.
The side bar includes: contacting surfaces confronting the facing surfaces of the faceplate and the backplate; and at least one paste-receiving groove formed on each contacting surface in a longitudinal direction, the paste-receiving groove(s) receiving adhesive paste for sealing the faceplate to the backplate.
The flat panel display device may further comprise at least one getter-receiving groove formed adjacent to the paste-receiving groove, the getter-receiving groove receiving a getter that is used for improving a vacuum degree of the flat panel display device and being directed to an effective area of the flat panel display device that is to realize images.
The adhesive paste is preferably provided on the paste-receiving groove such that the center portion of the adhesive paste is higher than the contacting surface of the side bar and the circumferential portion of the adhesive paste is lower than the contacting surface of the side bar.